1. Field of the Invention
The present invention relates to a connecting device that can be applied to a mobile electronic device, such as a mobile audio visual device or a cellular phone, and also relates to an antenna device and a receiving device of the connecting device.
2. Description of the Related Art
Since a mobile electronic device obtains a large screen and high performance, and since a television (TV) tuner becomes small and thin, a mobile electronic device terminal that user can watch and listen to television is being widely spread.
Also, in recent years, an electronic device such as a communication terminal, for example, a cellular phone frequently has a function for receiving broadcast waves of FM radio, digital radio, or digital television.
A user may listen to the sound of the electronic device with an earphone (including headphone) through an earphone cable that uses a coaxial cable.
Also, when an electronic device such as a cellular phone includes a television receiver, a user listens to the sound with an earphone while a cable for the earphone is formed as a shielded cable and hence functions as a receiving antenna, so that the cable is also used for transmission of a high-frequency signal.
For example, Japanese Patent No. 4003671 and Japanese Patent No. 4123262 disclose such earphone antennas.